Trezör® Bridge® — Connect Your Web3 World Securely™

Trezör Bridge is a lightweight, secure communication layer that connects your Trezor hardware wallet to web applications. It enables browser-based dApps and wallet interfaces to interact with your device without exposing private keys — bridging the gap between web convenience and hardware-grade security.

What is Trezör Bridge?

Trezör Bridge is an official helper application that runs on your computer and provides a secure, authenticated channel between browser-based web apps and your Trezor hardware device. When a website requests access to a Trezor device, Bridge mediates the request and ensures only explicitly allowed actions are forwarded to the device for user confirmation.

Why it matters

Modern web wallets and dApps should never have access to private keys. Bridge enables a robust workflow where:

The web application can compose transaction data and request a signature.
Bridge relays the request to the local Trezor device with integrity checks.
You verify transaction details directly on the device’s screen and approve or reject the action.

This separation drastically reduces the risk posed by compromised browsers or malicious websites because final approval always happens on the hardware device under your control.

Key features

Secure RPC channel: Encrypted local IPC using mutually authenticated TLS between browser and Bridge.
Origin binding: Bridge validates which web origins request access and presents that context during approval on-device.
Automatic device discovery: Detects connected Trezor devices and surfaces them to supported web pages.
Cross-platform: Available for Windows, macOS, and Linux (DEB/APPIMAGE). Lightweight and auto-launching with the browser when installed.
Minimal permissions: Runs with minimal system privileges and exposes only necessary APIs to the browser.

Multiple instance support: Handle multiple Trezor devices without conflicting sessions.
Session management: Allow or revoke site access per-session or permanently via Bridge settings.
Developer tooling: Localhost-only modes, verbose logging for debug, and test keys for safe development.
PSBT support: Export and coordinate Partially Signed Bitcoin Transactions for air-gapped workflows and multisig setups.

Security model — layered and transparent

The security model for Bridge is intentionally simple and layered to reduce attack surface:

Device as root of trust: All signing requires direct approval on the Trezor screen. Bridge cannot sign on behalf of the device.
Origin verification: Bridge records the requesting web origin and includes that information during device confirmation prompts so you can verify where the request came from.
Localhost-only by default: Bridge binds to local interfaces and will not accept remote connections unless explicitly configured for advanced setups.
Signed updates & checksums: Bridge releases are signed and published with checksums; users should install only from official sources and verify integrity.

Installing Bridge — quick guide

Installation typically takes a few steps and is straightforward across operating systems:

Quick checklist: Download from the official site → verify checksum if possible → install → open browser and allow Bridge when prompted.

Windows

Download the Windows installer (.exe) from the official Trezor website.
Run the installer and follow the prompts. Administrator privileges are required for system-level certificate installation used for localhost TLS bindings.
Open your browser and visit a supported dApp. The site will request Trezor access; Bridge will prompt you to allow the connection.

macOS

Download the macOS package (.dmg) and install.
On first run, macOS may prompt for permissions to allow network sockets — approve these for normal operation.
The browser will request Bridge when a dApp needs hardware signing; approve the prompt and follow on-device verification.

Linux

We provide AppImage and DEB packages. Follow distro-specific instructions and ensure you have the required udev rules for USB device access.

Using Bridge with web wallets & dApps

Bridge integrates with popular wallet libraries and frameworks (e.g., WebUSB/WebHID fallbacks where supported). Typical flow:

The dApp detects Bridge and lists available Trezor devices.
User selects a device and authorizes access via a browser prompt that Bridge mediates.
The dApp builds a transaction or signs data and sends the signing request to Bridge.
Bridge forwards the request to the device; the device displays the origin and transaction details for user confirmation.
After user approval, the signed transaction is returned to the dApp for broadcast.

Developer notes & integration tips

Developers building dApps should follow best practices to integrate safely with Bridge:

Always display the full transaction details to users before requesting a signature; do not rely on Bridge/device prompts as the only UX element.
Use explicit origin-checking and avoid overly broad permissions. Prompt users clearly when you request hardware access.
Provide a fallback path for users without Bridge — a read-only mode, or guidance for installing Bridge.
During development, use localhost testing modes and dedicated test networks to avoid exposing mainnet funds.

Privacy & telemetry

Bridge is designed with privacy in mind. It collects minimal telemetry by default, primarily for crash reporting and usage statistics. Telemetry can be disabled in Bridge settings. Bridge does not send wallet addresses, seed material, or transaction payloads to remote servers — all signing remains local to your device and machine.

Troubleshooting common issues

Bridge not detected by browser

Ensure Bridge is running in the system tray. Restart the application and the browser.
On Windows, confirm the installer was run with administrator privileges so TLS bindings were created.
Check for conflicting extensions or software that might intercept local sockets or certificates.

Device not found

Try a different USB cable or port. Avoid unpowered hubs during initial troubleshooting.
Check udev rules on Linux; ensure your user has access to USB devices.
Confirm the device is unlocked (PIN entered) and not in firmware update mode.

Error: origin mismatch

If Bridge reports an origin mismatch, it means the requesting web page’s origin does not match expectations. Close the dApp and re-open it from the correct origin. Do not authorize suspicious or unfamiliar pages.

Advanced & enterprise uses

For organizations and advanced users, Bridge can be configured to support specialized workflows:

Policy-managed deployments: IT teams can deploy Bridge with preconfigured settings, whitelisted origins, and enterprise logging to streamline usage across many workstations.
Air-gapped signing: Use PSBT export to move unsigned transactions to an air-gapped machine for signing with a Trezor, then return signed PSBTs for broadcast.
CI/CD integrations: For testnet automation, developers can use Bridge in secure test environments with restricted device access and test accounts.

Updates & patching

Bridge releases occasionally include bug fixes, security hardening, and developer improvements. Auto-update is available on supported platforms, but users may disable it and install manually if they prefer to verify each release. Always install Bridge updates from official channels and verify checksums where available.

Compatibility table

Component	Supported	Notes
Windows 10/11	Yes	Installer (.exe) with TLS binding
macOS 11+	Yes	DMG package; grant network permissions on first run
Linux (Deb/AppImage)	Yes	Set udev rules for USB access
Major browsers	Yes	Chrome, Edge, Firefox (via extension / native messaging), Brave
Headless servers	Limited	Not recommended for production signing; use PSBT/air-gapped workflows

FAQ

Do I need Bridge to use my Trezor?: Not always — Trezor Suite (desktop) talks directly to devices without Bridge. Bridge is required when using certain browser-based dApps that rely on the local Bridge protocol to communicate with the device.
Is Bridge safe to run on public networks?: Bridge binds to local interfaces and is not intended to accept remote connections by default. For security, run Bridge only on trusted machines and disable remote access unless you understand the implications.
Can Bridge be used with multiple profiles/devices?: Yes—Bridge supports multiple connected Trezor devices and separate browser sessions. Use explicit session management to keep access scoped per-site.

Legal & compliance

Bridge is distributed as a helper application for interacting with Trezor hardware. It is a tool for self-custody only; Trezor Bridge does not provide custody services or financial advice. Users are responsible for their own compliance with local laws and regulations when transacting digital assets.

Closing thoughts

Trezör Bridge brings the convenience of web-based applications together with the uncompromising security of hardware wallets. By keeping signing decisions on-device and limiting the browser’s ability to act without user consent, Bridge ensures you retain control of your keys while still enjoying the rich ecosystem of Web3 interfaces. Install Bridge from official sources, follow security best practices, and treat the device-screen verification step as your final gatekeeper for every transaction.